Combination gas heater



E. C. ADAMS COMBINATION GAS HEATER Filed March 6, 1951 d0000n0000m000000m0/ Sept. 25, 1933.

1/ A I I [Mi /II ll INVENTOR ZZZ/ w)? f/fzwi W5 TORNE Patented Sept. 26, 1933 UNITED STATES PATENTOFFICE Application March 6, 1931. Serial No. 520,572 Claims. (c1.12s-90) My invention relates to room heaters and particularly to combination radiant and circulator gas heaters.

An object of my invention is to provide a rela- 5 tively simple, compact, and highlyefiicient combination radiant and circulator heater structure.

Another object of my invention is to provide a combined radiant and circulator gas heater in which'the venting between the heater and the circulator or heat exchanger is confined to the area of the combustion space within the radiants.

Another object of my invention is to provide means in a combination radiant and circulator heater that shall ensure the complete combustion of the gas within the combustion space in the radiants, under abnormal operating conditions as well as under normal operating conditions.

Another object of my invention is to provide means for effecting a highly eificient heat-interchange, said means permitting of an auxiliary flow of fair to be heated, in addition to the .main flow of .air.

A still further object of my invention-is to provide' means permitting the adjustment by relatively simple means of the amount of or the speed of travel of the products of combustion through the heat-exchanger.

Other objects of my invention will either be apparent from the description of the device embodying my invention or will be pointed'ou't in the course of said description.

In practicingmy invention, I provide a suitable housing, .the greater portion of which may be made of sheet metal elements, the housing having anopenfront in whichis located a back wall of .a refractory material, in which arelocated a plurality of open face radiants providing the combustion space for the gas burned therein by a-suitable gas burner located below the radiants. This plurality of radiants is used for convenience of manufacture and replacement and a single large radiant unit may be used. A heat-exchanger providing one path for the products of combustion and another path for the air to be heated, is locatedwithin the housing, and has inlet and outlet openings respectively for the products of combustion. A grill .in the front upper portion of the housing provides an auxiliary path for'air to be heated. An adjustable bafile is 60 located within the heat-exchanger.

, In the single sheet of drawing,

Figure 1 is a view, in front elevation, of a combined'radiant and circulator heater embodying my invention, only one radiant being shown therein,

Fig. 2 is a view, in sideelevation, of the device shown in Fig. 1,,

Fig. 3 'is a view, in vertical lateral section, of the device embodying my invention and taken on the line III'-III of Fig. 1,

Fig. 4 is a view, in horizontal section, taken on the line IVIV of Fig. 3, and,

Fig. 5 is'a view, in rear elevation, of a radiant used in my improved heater.

While I have illustrated in the drawing and 66- will now describe a particular embodiment of a structure either embodying my invention or with which the devices particularly embodying 'my invention are operatively associated, I desire it to be understood that this is done for illustrative purposes only, andrthat I do not desire to be limited to the particular detailsof construction shown as these illustrate that form of the device embodying .my invention best adapted to practice thesame'.

LA heater housing designated by 11 may include an ornamental open front member 12 and anopen topboxstructure 13 associated therewith. Legs 14 and 16 of any suitable type and design mayibe. provided and secured in any well known manner to the box 11. A perforated cover 17 is located onthe top of the casing and. may be held thereagains't by any suitable means (not shown). The member 12 may be made of a suitable ornamental Light-weight casting in order that the heater mayhave a pleasing front appearance". The member 12 may include a lower projecting ledge 18 and an upper" portion 19 also projecting forwardly of the plane of the side portions thereof and the lower arcuate part of portion .191may .be perforated as shown at 21 in Figs. 1 and 3 of the drawing for apurpose to be hereinafter. set forth.

l A clayba ck wa1122 of substantially inverted L-sha'pe; and while I have shown a refractory back wall of relatively large mass, I do not desire to be limited thereto, as the back wall might'be made. of .metal and of relatively small mass, or the front wall of the heat-exchanger unit to be later described may serve the same purpose. The construction and materials I have selected are those suited for long life. The back wall is provided with an outlet ope'ning'23 therethrough, which opening is substantially'as wide as the space occupied by a plurality of open face radiants 24, which radiants may be of any suitable or desired type usually employed in radiant gas heaters. The size and shape of the individual radiants 24 is such that their upper end portions fit relatively closely within the overhanging'and 1 downwardly-extending portion 26 of the "back wall. By closely fitting I do not desire to convey the impression that there can be no clearance between the two members 26 and 24, but I do wish to point, out that the fit therebetween shall be close enough so that practically little .or no air will enter the outlet 23 in the clearance space therebetween, thus making it necessary that all of the air required for the proper combustion of gas being burned within the radiants, shall enter the radiants either at the bottom or through the open face fronts thereof. I 3

A gas burner manifold 27 is suitably supported within the housing 11 in proper operative position below the radiants 24 and a gas valve 28 is provided in a manner well known in the art to control the amount of gas being burned. I have not shown a supporting means for the manifold as any suitable or desired means of this kind may beemployedl Itis further to be understood that the back wall is suitably supportedon a plane support 29 which may be a separate plate provided for thatpurpose, or which may be a part of a heat-exchanger now to be described.

A heat-exchanger 31 includes a boxlike structure which is substantially closed at four sides thereof, and which is provided with a plurality of conduits 32 therein extending in a vertical direction and located in spaced relation relatively to each other. The walls of the conduits at their ends are suitably secured to the top and bottom walls of the heat-exchanger structure to prevent products of combustion flowing out of the heatexchanger at any point other than a flue 33 at 35 the rear thereof, which flue fits into an outlet opening 34 in the rear wall of housing 11 and which is provided for connecting the heater to a chimney or stack flue in the usual fashion.

. The heat-exchanger 31 is provided with a rela- 40- tively narrow but relatively long inlet opening 36 which fits into the outlet opening 23 in the back wall 22. e

A baffle structure 3'7 includes'a vertica11y-extending plate 38 and a horizontally-extending plate 39 pivotally mountedat one of its edges to the lower end of the vertical portion and having its free end formed to project forwardly between and around the conduits 32, the bafile being located between the conduits 32 and the back wall of the heat-exchanger 31. An adjusting knob 40 may be located at the side of the casing 11 to permit of adjusting the position of portion 39 for regulating the flue draft.

While proper and com'pletecombustion of the gas will take place within the radiants'themselves and before the products of combustion reach the outlet opening 23, so long as normal oxygen-supply conditions prevail, it'may happen that a gas heater of this kind will be called upon to operate in a substantially closed chamber or room, and I have found that complete combustion'will not occur entirely within the radiants under these conditions. In order to supply an auxiliary amount of oxygen which will ensure the complete combustion within the radiants themselves, I provide two relatively small j openings 41 in the back wall of eachradiant. Cooperating with these openings are a pair of grooves 42 (see Fig. 1)' located in the front surface of the back wall and extendingfrom the bottom edge thereof and up to substantially the top edge of openings 41, thus conducting combustion air to the radiants at a most advantageous point for insuring complete combustion. v i I A radiant-type gas-fired room heater as cer-.

diant eiiiciency of a radiant type of heater ranges from about 25% to about 30%, and if a radiant heater is used in a fuly vented fireplace, the above mentioned efficiency will be about the maximum that can be obtained. In order to increase the eiilciency circulator heaters were designed but these had to be constructed along different lines in order to be emcient, and when both types were combined in a single structure concessions had to be' made in order to get the desired higher efliciency.

In the device embodying my invention the construction and arrangement of the radiants and the back wall is such that the combustion is effected completely in the combustion space within the clay radiants, and due to the close fit of the upper ends of the radiants in the openings in the back wall the amount of air entering the heat-exchanger is limited substantially to that necessary to provide or effect the complete combustion of the fuel consumed within the radiants or, in other words, the air and gas entering the radiants. The fit of the radiants within the back wall is, as has already beenhereinbefore set forth, such that relatively little air may enter the outlet opening 23 by flowing past the upper ends of therespective radiants or between the upper ends of the radiants and the back wall itself. The

exclusion of any excess air from the flue spaces l were possible to supply exactly the required amount of air to completely burn natural gas, an analysis of the flue gases would show about 12% of CO2, but I have found as the result of many tests, that so much excess air enters a radiant heater of the usual kind that the percentage of CO2 is about 1 /2%. In well designed totally enclosed heaters the secondary air openings are made of suchsize as to supply only enough secondary air to support complete combustion, but because this secondary air cannot be directed perfectly into the flame the percentage of CO2 rare- 4 1y exceeds 5% to 6%. Tests on a number of gas heaters embodying my present invention have shown that the percentage of CO2 is 9% or over 75% perfect,and I attribute this to the fact that the amount of excess air mixed with or becoming a part of the gases of combustion is relatively very small.

Itis obvious that convection currents of heated air will flow upwardly in the conduits 32, which are open at both ends, in the direction indicated 4 by the arrows 46, this main path being substantially free and unobstructed. The products of combustion will flow in a circuitous path, indicated by the arrows 47, in the heat-exchanger and out through the flue 33. circuitous path traversed by the products of com- Because of the bustion' a very largepercentage 0f the heat in the products of combustion will -be transferred into "the air fiowingthrough the'conduits 3 2.

The upper part of the back'wall," and particularly the overhanging portion'26 will be-'raised toarelatively high temperature so that an auxiliary path for convection currents of air will be established through the openings 21 in the grill and upwardly out through theperforated cover 17, this air being heated not only by the upper portion 01" the back wall but also by the upper portion of the heat-exchanger.

Another advantage of my invention as illustrated is that an operator or user of a gas room heater of my improved type may obtain any desired degree of humidity within a relatively wide range, by merely varying the position of the baflie plate, as has been hereinbefore set forth because this baffle controls the amountrof the products of combustion which may be projected back into the room and, as such products contain moisture, humidity control results.

The device embodying my invention thus provides a highly efficient combined radiant and circulator heater, the dimensions whereof are a minimum because of the relatively high temperatures at which the products of combustion enter the heat exchanger. It provides also means for obtaining relatively strong main andauxiliary convection currents of heated air, and a person or object within range of the radiant heat from the front of the heater will be subject to the radiant heat therefrom. The degree of humidity in the room can also be controlled by the adjustment of the battle in the heat exchanger.

I desire that my invention be limited only by the prior art, and in accordance with the appended claims.

I claim as my invention:

1. A heating appliance comprising in combination an open-front radiant heater consisting of an outer housing having an opening in its front, a perforated cover on its top, and an outwardly projecting portion above said front opening perforat-- ed on its under side to permit the circulation of air through it and out said cover, a burner supported in said housing back of said front opening, a heat-reflecting back wall mounted in the rear of said burner, a radiant mounted over said burner with its upper end engaged in an orifice in said back wall and in such a way that only the products of combustion passing through said radiant are permitted to pass through said orifice, an enclosed circulator chamber forming casing'mounted back of said back wall in spaced relation to said outer housing, an inlet connection connecting said casing to the orifice in said back wall, a fiue connection extended from said casing through said housing, and an open ended circulating conduit extended vertically through said circulator casing.

2. A heating appliance comprising in combination an open-front radiant heater consisting of an outer housing having an opening in its front,

a perforated cover on its top, and an outwardly projecting portion above said front opening perforated on its under side to permit the circulation of air through it and out said cover, a burner supported in said housing back of said front opening, an inverted substantially L-shaped heat-reflecting back wall mounted in the rear of said burner, a radiant mounted over said burner withits upper end engaged in an orifice in said back wall and in such a way that only the products of combustion passingthrough' said radiant are permittedto pass-jthrough said oriillce, an enclosed circulatorcliamber forming casing mounted back of saidbackwalL an inlet connection connecting said casing to the orifice in said back wall, a flue connection extended from-said casing throughsa'id housing, an open ended conduit extended vertically through said circulator casing, and a baffle wall structure in said casing arranged to provide a circuitous path for the products of combustion through said circulator chamber.

3. A heating appliance comprising in combination an open-front radiant heater consisting of a burner, a heat-reflecting back wall mount ed in the rear of said burner, a radiant mounted over said burner with its upper end engaged in an orifice in said back wall and in such a way that only the products of combustion passing through said radiant are permitted to passthrough said orifice, an enclosed circulator champer forming casing mounted back of said back wall, an inlet connection connecting said casing to the orifice in said back wall, a flue con nection in the side of said casing opposite said back wall, a bafiie wall structure in said casing arranged to provide a circuitous path for the products of combustion through said circulator chamber, and an adjustable bafiie wall portion mounted on one end of said bafile wall and adaptto function as a damper for controlling the draft in said chamber.

4. A heating appliance comprising in combination an open-front radiant heater consisting of an outer housing having an opening in its front, a perforated cover on its top, and an outwardly projecting portion above said front opening perforated on its under side to permit the circulation of air through it and out said cover, a burner supported in said housing back of said front opening, an inverted substantially L- shaped heat-reflecting back wall mounted in the rear of said burner, a plurality of radiants mounted over said burner with their upper ends engaged in an orifice in said back wall and in such a way that only the products of combustion passing through said radiants are permitted the rear of said back wall and in spaced rela-' tion with said outer housing, an inlet connection connecting said casing to the orifice in said back wall, a fiue connection extended from said casing through said housing, aplurality of open ended circulating conduits extended vertically through said circulator casing, and a baflie wall structure in said casing arranged to provide a circuitous path for the products of combustion through the circulator chamber.

5. A heating appliance comprising in combination an open-front radiant heater consisting of an outer housing having an opening in its front, a perforated cover on its top, and an outwardly projecting portion above said front opening perforated on its under side to permit the circulation of air through it and out said cover, a burner supported in said housing back of said front opening, an inverted substantially L- shaped heat-reflecting back wall mounted in the rear of said burner, a plurality of radiants mounted over said burner with their upper ends engaged in an orifice in said back wall and in such a way that only the products of combustion passing through said radiants are permitted to pass through said orifice, an enclosed circulator chamber forming casing mounted back of casing, a baffie wall structure in said casing arranged to provide a circuitous path for the products of combustion through said circulator chamber, and a. bottom wall for said housing having openings in it registering with the ends of said circulating conduits.

EDWIN C. ADAMS. 

